Geant



Sheet 2.

2 Sheets No Model.)

H. OQSERGEANT.

AIR COMPRESSOR N. PETERS. Photo-Lithographer, wmingmn, D. C.

UNITED STATES PATENT OFFICE.

HENRY CLARK SERGEANT, OF NEW YORK, N. Y., ASSIGNOR TO THE INGER- SOLL-SERGEANT ROCK DRILL COMPANY, OF SAME PLACE.

AIR-COMPRESSOR.

SPECIFICATION forming part of Letters Patent No. 415,822, dated November 26, 1889.

' Application filed January 4, 1889. Serial No. 295,403. (No model.)

To all whmn it may concern:

Be it known that I, HENRY CLARK SER- GEANT, a citizen of the United States, residing in the city and county of New York and State of New York, have invented a new and useful Improvement in Air-Compressors, of which the following is a specification, reference being had to the accompanying drawings.

The object of this invention is to provide a compressor for the economical compression of air to a very high tension, and especially to obtain a compressor for such work which is of simple construction, which will be as nearly as practicable free from leakage, and which may be very easily kept in order and I repaired.

provement with reference to the drawin s I will first describe the construction and operation of a compressor embodying my imsection in the line as x of Fig. 3; Fig. 5, av

transverse vertical section in the line 11 y of Fig. 3; and Fig. 6, a transverse section in the line 2' z of Fig. 3. The said transverse sections are all taken viewed from the right.

Similar letters of reference indicate corre sponding parts in the several figures.-

A and B designate two compressor-cylinders of unequal size arranged end to end.

C and D designate two connected pistons fitted, respectively, to the two cylinders for the purpose of first compressing the air to a certain degree in the larger cylinder and afterward further producing and completing its compression in the smaller cylinder. The cylinders are respectively fitted at their outer ends with air-tight heads A and B; but they are represented in free intercommunication at their inner or adjacent ends. The larger cylinder A is represented as provided at its inner end with an annular head A to which the smaller cylinder B, surrounded by a water-jacket B is secured, the said head A having a central opening to the inner end of to leakage is reduced to a minimum.

the smaller cylinder. The larger cylinder is also represented as surrounded by a waterjacket A In the inner cylinder-head A there are several openings a, (see Fig. 5,) through which the inner end of the larger cylinder is always in free communication with the atmosphere. As the inner ends of the two cylinders are in free communication with each other, the inner end of the smaller cylinder is only in communication with the atmosphere through the said openings at.

In or on the outer head A of the larger cylinder there is a valve-box E, in which are valves 6, of any suitable kind, which open outward from the said cylinder into said box, and from this box a passage or conduit J, formed partly on the cylinder-jacket A and partly on that B leads to a valve-box F, (see Figs. 3 and 6,) provided in or on the head B of the smaller cylinder. In this box F are valves f, of any suitable kind, which open from the said box to the outer end of the smaller cylinder.

The cylinder-head B has also provided in it another valve-box G, (see Figs. 3 and 6,) which contains valves g, of any suitable kind opening outward into the said box, which is always in communication with the discharge pipe or passage through which the com pletelycompressed air is delivered. In the example represented there is a discharge-passage H, formed partly on each of the water-jackets of the cylinders and intended to have a discharge-pipe connected with it at H. (See Figs. 3 and a.)

The heads of the pistons C D may be packed in any well-known manner, and may be permanently connected together in any suitable way. In the example represented they are connected by a hollow trunk b and by a piston-rod c, which passes through a stuffingbox (1, provided for it in the head A of the outer cylinder. This stuffing-box contains 5 the only packing used in the compressor, except that of the piston-heads, and, as this box is in the larger cylinder, in which the primary compression takes place, the liability The piston C of the larger cylinder may be fitted with any suitable kind of valve or valves that will open from the inner end toward the outer end of the said cylinder. In the example represented there is a single valve consisting of a disk I, of metal, having a central hub I, which is fitted to slide upon the piston-rod a distance limited by a stopshoulder c on said red, as shown in Fig. This valve opens and closes a large number of openings 1', provided in the piston-head. The piston D of the smaller cylinderis valveless.

Passagesj, for the circulation of water to and from the Water-jackets for cooling the cylinders, are shown intersecting the air-passages J and H, and oil-passages j, for oiling the cylinders and pistons, are shown intersecting the air-passage J. These water and oil passages are no part of the improvement, and are only mentioned here to prevent confusion of the parts of the drawings.

The air-compressor thus constructed is to be operated by power applied directly to the piston-rod c, to produce its reciprocating mo tion. In Figs. 1 and 2 this rod is represented as connected for this purpose with the same cross-head as the piston-rod Z of a reciprocatin g steam-engine. The larger cylinder A, which is furnished, as shown in Fig. 4:, with horizontal lateral flanges 172, one on each side of its water-jacket, is represented in Figs. 1 and 2 as supported and secured by these flanges on the same bed-plate or frameK with the steam-engine, and the smaller cylinder is represented as supported by being secured to the head A of the larger cylinder independently of the framing or bedplate and overhanging the latter. This method of supporting the smaller cylinder allows it to be easily removed to afford convenient access to the pistons, which can be withdrawn when the smaller cylinder has been removed and the rod has been disconnected from the crosshead. The cylinder-head A can also be removed entirely after theremoval of the pistons and their rod.

To explain the operation of the compressor, I will first suppose the pistons to be moving to the right of Fig. 3. The piston-valvelwill -now be open. Air which is freely supplied to the inner end of the larger cylinder through the openings a, which are always in free comm unication with the atmosphere,will now pass through the said valve I to the larger cylinder and fill it. On the return-stroke the air which had been thus admitted will be compressed by the piston C in the larger cylinder, the valves 9 of which will be thereby opened by the pressure due to this compression to allow the said air to pass to and through the passage or conduit J to the valves f, which will be opened by the said pressure to admit the said air to pass through them into the smaller cylinder, the valves 9 being meanwhile closed by the pressure in the receiver, with which there is connection at H. As this stroke continues, the air is further compressed by its being forced into the smaller space within the cylinder B as compared with thatin A. lVhen the pistons again move to the right, the air in the smaller cylinder B is compressed and forced out therefrom through the valves g by the pressure thus imparted to it, while a fresh charge of air is taken into the cylinder A between its outer end and its piston through the openings to and pistonvalve I, as hereinbefore described. The areas of the larger and smaller cylinders and pistons may be so proportioned to each other and to the degree of compression desired to be attained that the work of compression will be equally divided between the two pistons, and power required to be exerted will be nearly the same in the two strokes of their reciprocating movement.

Throughout this specification I have referred to my invention as relating to air-compressors; but a compressor constructed according to my invention is obviously also applicable to the compression of gases, and in such case the inlet-openings a, instead of communicating with the atmosphere, will communicate with the source from which the supply is.

secure by Letters Patent, is

The combination, in a compressor, of two single acting cylinders of unequal caliber arranged in line with each other, being in free intercommunication with each other and with the atmosphere or source of supply at their inner or adjacent ends and having heads at their outer ends, a passage or conduit outside the cylinden between the said heads, a discharge-valve in the head at the outer end of the larger cylinder between the said cylinder and said passage or conduit, an inletvalve in the head at the outer end of the smaller cylinder between the said cylinder and said passage or conduit, two connected pistons fitted to said cylinders, the piston of the smaller cylinder being valveless, an inletvalve in the larger piston opening toward the outer end of its cylinder and discharge-valves in the head at the outer end of the smaller cylinder,substantially as herein described.

HENRY CLARK SERGEANT.

\Vitnesses:

FREDK. HAYNES, ARTHUR H. GAMBLIN.

IIO 

